In zoom lenses where the focal length is controlled while holding an accurate focus, one lens system moves to change the focal length while at the same time, another lens system must correct the focus. For this reason, at least two lens groups must be moved in a zoom lens. To enable improved performance over the entire zoom range, higher magnification, and a more compact and easy-to-use design, most PENTAX zoom lenses use three to five moving lens groups instead of only two. These lenses incorporate PENTAX's advanced technology features such as our inner zoom which moves only the internal lens system without changing the total lens length and nonlinear movement zoom where each lens system performs complex movements.
The new lenses from Pentax are a refresh of their classic film lenses, now optimized for digital cameras. The five prime lenses vary in length from 15mm to 70mm, and feature super-compact designs. They all have Pentax’s quick shift focus system, which allows a user to fine-tune a set autofocus without needing to manually shift switches or programs, and are available in both black and silver color options.
PENTAX interchangeable lenses use our unique multicoating for reducing the surface reflections to approximately 1/10 of single-layer film coatings. This coating increases the transmissivity of light over the entire visible light range and also nearly completely cuts out harmful UV light. This coating also reduces ghosting and flare under backlighting and other adverse conditions for providing images with a high sense of transparency.
Moreover, some lenses use PENTAX's exclusive ghostless coating for reducing reflections from specific types of light for minimizing the occurrence of ghosting. PENTAX performs the optimum control of each coating for each lens to match the lens configuration, glass characteristics, and other factors.
Also, flocking and paint are combined for preventing reflections inside the lens barrel. A light shielding mechanism is installed to prevent scattering of light from a lens within the lens group together with other measures for minimizing ghosting and flare.
Ricoh has announced a new zoom lens for Pentax DSLR cameras. This lens is HD PENTAX DA 16-85mm f/3.5-5.6 ED DC WR Lens. Its 16 optical elements in 12 groups include one ED element and three aspherical elements. The lens will be available in November for $749.95.